What controls the natural menstrual cycle?
Only women capable of a menstrual cycle can get pregnant naturally. The body makes chemicals and proteins called neurotransmitters and hormones which create the menstrual cycle. The neurotransmitters from the brain tell the pituitary, an organ found in the brain, to make and release protein signals that go to the ovary where an egg is developed. Estrogen is made by the ovary to help the egg develop and after the egg is released (ovulation) progesterone is made by the ovary. Both estrogen and progesterone are the female hormones that regulate the menstrual bleeding from the uterus. Estrogen makes the inside lining of the uterus get thick and full of blood vessels. Progesterone then matures the cells lining the inside of the uterus and causes the cells to fill with chemicals which will be needed. This is all to prepare for pregnancy. If a pregnancy does not happen, then the progesterone and estrogen hormone levels drop. Without enough progesterone the cells lining the inside of the uteru
